Closure cap and method of making



June 25, 1963 H. E. STOVER ETAL CLOSURE CAP AND METHOD OF MAKING Filed June 10. 1960 2 Sheets-Sheet 1 lq s m M w 0 a v! 1 w; ,fi w A I E D un g 0 5 H/ WM ///H B a w.

lI 5 a June 25, 1963 H. E. STOVER ETAL CLOSURE CAP AND METHOD OF MAKING 2 Sheets-Sheet 2 Filed June 10. 1960 was vln TO Y INVENT #4919) 5 @910 04015; 14C

3,095,194 CLOSURE CAP AND METHOD OF MAKHNG Harry E. Stover and Daniel ll). Acton, Lancaster, Ohio,

assignors to Anchor Hocking Glass Corporation, Lancaster, ()hio, a corporation of Delaware Filed June 19, 196i Ser. No. 35,201 1 (Ilairn. (Cl. 215-40) The present invention relates to the sealing art and more particularly to an improved closure cap adapted to be mounted on a container to form a sealed package.

Closure caps are widely used to hermetically seal contain'ers. Such closure caps utilize a sealing gasket which cooperates with the rim of a container when the closure cap is applied thereto to form a hermetic seal.

One type of sealing gasket commonly used is a socalled cut-ring gasket which is cut from a tube of vulcanized rubber or other suitable material. Another type of gasket commonly used is a flowed-in type gasket in which a gasket material is flowed into the closure and then heat is applied to harden it.

It has been found that during handling if a cap on a sealed package is bumped against another cap a portion of the skirt of the closure may be deflected inwardly so as to result in a distortion of the metal of the gasketreceiving channel and a release of compression force on the sealing gasket which causes loss of vacuum. This is especially true if the sealing gasket is a cut-ring type gasket, but will often occur with a flowed-in type gasket. Since such sealed packages are handled in great quantities by retail stores, the problem of scaled packages losing their hermetic seal because of bumping and deformation of the cap is an important one.

The present invention overcomes this disadvantage and has for one of its objects the provision of an improved closure cap having means to prevent loss of compression force on the sealing gasket as a result of a blow.

Another object of the present invention is to provide an improved closure cap which will remain in hermetically sealed relationship with the container even if a portion of the cap is distorted by bumping.

Another object of the present invention is the provision of an improved method of forming an improved closure cap having a bump-proof feature.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claim, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a side elevational view showing a closure cap in position on a container to form a sealed package;

FIG. 2 is a sectional view showing the usual closure cap now in general use before it is damaged;

FIG. 3 is a sectional View of the closure cap shown in FIG. 2 showing the deformation which appears in the sealing gasket after a portion of the skirt has been deflected inwardly as a result of a blow;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 1 showing the damage-resistant feature of the present invention and showing the normal position of the gasket and the cap;

FIG. 5 is a sectional view similar to FIG. 4 showing the undisturbed position of the gasket after the skirt of the closure cap has been distorted as a result of a bump;

FIG. 5A is a diagrammatic sectional view similar to 3,5,lil4 Patented June 25, 1963 FIG. 5 showing one variation in the manner in which the cap of the present invention operates;

FIG. 6 is a sectional view showing the first step in the improved method of forming the cap of the present invention;

FIG. 7 is a similar view showing the second step in the formation of the cap;

FIG. 8 is a view showing the lug-forming step in the formation of the cap;

FIG. 9 is a sectional view showing the fourth step in the formation of the cap;

FIG. 10 is a similar view showing the last step in the formation of the cap; and

FIG. 11 is a side view partly in section showing the completed closure.

Referring to the drawings and more particularly to FIGS. 2 and 3 which show a closure cap in common use today, the closure cap 1 is provided with a cover portion 2 having a gasket-receiving channel 3 therein and a skirt portion 4 depending therefrom having the usual curled edge to form a bead 5. A suitable lacquer coating (not shown protects the closure cap from rust or corrosion. Suitable spaced locking lugs 6 (FIG. 11) are formed in the bead 5 and adapted to cooperate with corresponding thread segments (not shown) on a container 7 to hold the cap 1 in place on the container, as shown in FIG. 1. While, for convenience, the application will be described in connection with a cap having locking lugs, it will be understood that it is within the scope of the present invention to be adapted to any type of closure cap.

A sealing gasket 8 is inserted in the gasket-receiving channel 3 of the cap and may be held therein by suitable adhesive (not shown). The sealing gasket shown in the drawings is a so-called cut-ring type gasket which is usually cut from a tube of vulcanized rubber and adhered to the closure cap by an adhesive. The sealing gasket 8 is adapted to cooperate with the rim 9 of the container 7 to form an air-tight hermetically sealed package. While the invention will be described in connection vwith a cute ring type gasket, it will be understood that it is within the scope of the present invention to use a flowed-in type gasket or a gasket which is moulded in place of the gasket-receiving channel 3 and that wherever the term sealing gaske ap ears herein, it is intended to include all types of sealing gaskets.

FIG. 2 shows the cap before it is damaged whereas FIG. 3 shows the cap after it has been damaged. It will be noted from FIG. 2 that the outer portion 3a of the gasket-receiving channel 3 has broken down due to the overhead sealing pressure. It will be noted from FIG. 3 that a portion 10 of the skirt 4 is deflected inwardly as a result of a blow, such as may be obtained when two containers are bumped together or when a container is dropped and that the gasketreceiving channel 3 tends to straighten out. The deformation of the portion 10 of the skirt and the consequent distortion of the gasket-receiving channel 3 releases the compression force on the gasket 8 thereby breaking the hermetic seal. It will be understood that sometimes there is no breakdown of the gasket-receiving channel 3 when the closure is under sealing pressure (not shown in drawing) and in that event a blow will raise the corner radius slightly thereby releasing the pressure on the gasket 8 and breaking the vacuum seal.

The improved cap of the present invention is shown in FIGS. 4 and 5 and overcomes this disadvantage by providing a peripheral head 11 (FIG. 4) in the corner between the skirt 4 and the gasket-receiving channel 3 to act as a shock-absorber and as an escapement for inwardly deflected metal as a result of a blow. The bumpproof head 11 is raised above the level of the gasket- 3 receiving channel 3 so it does not come into contact with any portion of the sealing gasket 8.

As illustrated in FIG. 5, a porton 12 of the skirt 4 has been deflected inwardly as a result of a blow. It will be noted that the inwardly deflected metal will escape into the bump-proof bead 11 which assumes the V-shape form 13 shown in FIG. 5. The inwardly deflected metal 12 will tend to straighten out and will not come into contact with the sealing gasket 8 and will not aifect the gasket-receiving channel 3. Hence, compression force on the sealing gasket 8 is not disturbed and the hermetic seal between the gasket 8 and the rim 9 of the container 7 is not broken.

It will be appreciated that variations in the escapement action of the bead may occur.

One such variation is shown in FIG. A where the portion 10a of the metal of the skirt has been deflected inwardly in a concave manner and the bead 11a is tilted outwardly. However, here again, it will be noted that the gasket-receiving channel 3 is not disturbed so that the compression force on gasket 8 is maintained. It will be understood that the escapement action will vary depending on the blow received by the cap.

The advantages of the closure of the present invention over the closure caps commonly in use today is readily seen by comparison of FIGS. 3 and 5. In FIG. 3 .the crushed metal 10 of the skirt 4 has distorted the gasketreceiving channel 3 so that the sealing pressure on the gasket 8 is released to break the seal whereas in FIGS. 3, 5 and 5A the peripheral bead 11 acts as an escapement for the distorted metal 12 so that there is no distortion of the gasket-receiving channel 3, no loss of compression on the gasket 8 and hence no break in the seal.

The present invention also provides an improved method of forming the closure of the present invention. This is shown in FIGS. 6 through 11.

The first step (not shown) in the formation of a closure is the stamping out of a cup-shaped closure shell 15 (FIG. 6) having the skirt portion 4, a cover portion 2 and a gasket-receiving channel 3. The edge of the skirt 4 is coaxed-in, as at (FIG. 6), to facilitate the subsequent curling step.

As shown in FIG. 6, the closure shell, as thus formed, is inserted in a nest 17 having an ejector and the gasket 8 is inserted in the gasket-receiving channel 3. Before the gasket 8 is inserted, "a suitable adhesive (not shown) may be applied to the gasket-receiving channel to adhere the gasket in place. It will be noted that the radius of the corner 16 of the shell 15 is greater than the radius of the corner 18 of the nest 17. The large corner radius of the shell 15 is used to locate and center the gasket 8 in the gasket-receiving channel 3- by permitting the gasket 8 to be held in place between corner radius 16 and the shoulder 19 formed by the gasketreceiving channel 3.

A first curling tool 21 then presses down on the coaxedin edge '20 of the shell 15 to form a first curl 22 in the skirt edge, as shown in FIG. '7. At the same time, the radius of the corner 16 of the shell 15 is reformed to conform to the radius of the corner 18 of the nest 17. A suitable pad 23 applies pressure to the gasket 8 so as to adhere the gasket to the shell and hold the gasket in place during the step of reforming the corner radius of the shell 15.

As shown in FIG. '8 the lugs 6 are then formed by a lug-forming tool 24 and, at the same time, the partially curled edge 22 (FIG. 7) of the skirt is curled into a full bead 5 (FIG. 11). The ejector 25 of the nest 17 is then raised as shown in FIG. 9 so as to raise the cover 16 of the closure cap 011 the corner 18- of the nest 17 and thereby leave a depression 26 between the corner 18 of the nest and the corner 16 of the cap.

A pressure tool 26 (FIG. 10) now applies downward pressure to the skirt 4 of the closure to reform the metal of the corner 16 of the closure shell downwardly into the space 26 to form the bump-proof head 11 around the peripheral edge between the skirt 4 and the cover 2. The completed cap is then ejected from the nest as shown in FIG. 11.

It will be understood that the expressions raised, lowered downward, etc. referred to in the description of the method of the present invention are used in connect-ion with the inverted position of the closure cap as shown in FIGS. 6 to 11. If the steps of the method were described in connection with the upright position of the cap as shown in FIGS. 4 and 5, the steps of the method would be described by using antonyms of these expres- SIOIlS.

It will be seen that the present invention provides an improved cap which is damage-resistant; which will maintain its hermetic seal with a container even after a portion of the cap has been deflected inwardly as a result of a blow; and which will prevent any blow from releasing the compression force on the gasket. The present invention also provides an improved method of forming the improved cap of the present invention.

As various changes may be made in the form, construction and arrangement of the parts herein, without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described our invention, we claim:

A closure cap having a cover portion and a depending skirt portion, a flat peripheral annular gasket-seating surface in said cover portion, the plane of said gasket seating surface being substantially parallel to and spaced above the plane of the cover portion, a sealing gasket seated on said gasket-seating surface, said sealing gasket having a peripheral outer edge and being of a diameter less than the diameter of the skirt portion of the closure cap so that its peripheral outer edge is spaced inwardly from the skirt portion, and a peripheral hollow clearance bead connecting said gasket-seating surface and said skirt portion, said bead extending above the plane of the gasketseating surface and being adapted to receive any inwardly deflected portion resulting from a blow to the cap and thereby prevent release of the compression force on the gasket.

References Citedin the'file of this patent UNITED STATES PATENTS 796,221 Jorgensen Aug. 1, 1905 1,272,859 Russell Iuly 16, 1918 1,605,850 Merole ..i Nov. 2, 1926 1,884,691 Holloway Oct. 25, 1932 2,362,421 Von Till Nov. 7, 1944 2,365,350 Marek -1 Dec. 19, 1944 2,412,794 White Dec. 17, 1946 2,920,778 Foye Jan. 12, 1960 FOREIGN PATENTS 16,645 Great Britain 1913 40,824 France May 17, 1932 660,381 Germany May 24, 1938 486,883 Italy Nov. 18, 1953 

